Grinding machine



J 1935- V c. J. HIGHBERG 2,003,713

GRINDING MACHINE Fiiled March 31, 1928 s Sheets-Sheet 1 h ZEI I I {Ill nI P In I June 1935- c. J. HIGHBERG 2,003,713

GRINDING MACHINE Filed March 31; 1928 3 Sheets-Sheet 2 Cdrle High bergJune 1935- c. J. HIGHBERG 2,003,713

' GRINDING \MAGHINE Filed March 31, 1928 3 Sheets-Sheet 3 Curls J: H'Lchben Patented June 4, 1935 PATENT OFFICE GRINDING MACHINE Carle J.Highberg, Worcester, Mass., assignor to The Heald Machine Company,

Worcester,

Mass, a corporation of Massachusetts Application March 31, 1928, SerialNo. 266,287

26 Claims.

The invention relates to internal grinding machines, and particularly tothe workholding and work rotating mechanism thereof. The invention isshown applied to an automatic internal grinding machine in which thegrinding operation is automatically terminated when each workpiece hasbeen ground to the desired internal diameter. Since the invention ofsuch automatic internal grinders, the production rate of smallinternally ground articles has been greatly increased, by theelimination of the previously necessary hand gauging. On such machines,however, manual chucking and unchucking of the workpieces betweensuccessive grinding operations is still the rule, and it is thesetime-consuming operations that have limited further increase in the rateof production.

More specifically the present invention provides so-called centerlessworkholding means, the workpiece being supported and held in positionduring the grinding operation by tangential rolls. The provision of suchis therefore, one object of the invention. A further object of theinvention is to render it unnecessary for the operator of the machine toposition the workpieces in the workholding means and remove themtherefrom and to this end the machine of the invention .providesautomatically operated mechanism which performs these functions.

Further objects and advantages of the invention will more fully appearfrom the following detailed description which, taken together with theaccompanying drawings, illustrates some embodiments of said invention.In said drawings:

Fig. 1 is a front elevation of an internal grinding machine showing theinvention applied thereto. 7

Fig. 2 is a fragmentary view partly in plan and partly in section,illustrating the workholding and 40 work rotating means and themagazine.

Fig. 3 is a sectional view on the line 3-3 of Fig. 1, showing theworkholding and work rotating mechanism in elevation.

Fig. 4 is an elevation of the left hand side of the machine.

Figs. 5 and 6 are fragmentary views of the magazine together with theescapement mechanism shown in two positions.

Fig. '7 is a schematic view illustrating the automatic means for causingthe carriage to travel to the idle position, fragments of the cross feedmechanism and the carriage controlling parts being shown in conjunctionwith a wiring diagram.

Like reference characters refer to like parts throughout the drawings.

Referring first to Fig. 1 an internal grinding machine is shown having areciprocatory table or carriage l by the reciprocation of which the 5grinding traverse is produced, the said table in this instancesupporting a wheel head 2 in which is journalle'd the usual spindle 3carrying the grinding wheel 4. The spindle driving means which causesthe rapid rotation of the grinding 10 wheel 4 is not herein disclosed,as such is well known in this art and any suitable form thereof may beprovided. Similarly, the aforesaid reciprocating motion of the table I,to cause the rotating wheel 4 to make the required interior trav- 15erse of a workpiece, may be imparted in any well known manner, but, asillustrative .of a specific embodiment of such, reference should be hadto United States Letters Patent No. 1,582,468, granted April 27, 1926 toHeald and Guild, which 20 shows fluid pressure actuating and reversingmechanism to produce the aforesaid traverse, and automatic means to stopthe grinding table or carriage when the grinding wheel is fullyseparated from the work, the table I of the present 25 invention beingshown in this position in Fig. 1. Said table I provides a pair of spacedadjustable dogs 5 and 6 which are adapted to alternately engage and movea reversing member 1, these parts constituting the controlling means ofthe 30 aforesaid actuating and reversing mechanism.

In this embodiment of the invention the wheel head 2 is carried by across slide, not shown, which is mounted on ways for movement transverseto the line of reciprocation of the table I, as is the 5 ordinarypractice in internal grinding machines. A cross feed screw to move theaforesaid cross slide is indicated by'the numeral 8 and, referring toFigs. 1 and '7 said cross feed screw is intermittently actuated in thefollowing manner:--a 40 ratchet wheel 9 is either directly or throughthe medium of reduction gearing connected to the screw shaft 8, and anactuating pawl I0 is normally out of engagement with said ratchet wheel,but when moved upwardly will engage and move it. The pawl I0 is carriedon the end of a pivoted member H, which also provides a roller l2 thatrides on and is raised by an adjustable cam member l3 at the end of eachworking stroke of the table I that carries the grinding wheelinposition. The cross feed screw 8 can also be actuated from a handwheel I 5 since, as aforesaid, the pawl I0 is normally out of engagementwith the ratchet 5, being held thus by a spring, not

shown, there being a. cam member I! which forces it toward the ratchetwheel only when the said pawl is raised.

Referring to Figs. 1, 2, 3 and 4, a bridge I8 is attached to the machineframeand spans the ways I9, I9 which support the table I thus allowingsaid table to move thereunder. This bridge I8 provides an upwardlyextending frame portion 20 which supports the work holding and workrotating meansand the work magazine. Extending horizontally from theright hand face of the frame portion 20 are a pair of studs 2I and 22upon which are mounted for rotation a pair of flanged rollers 23 and 24respectively, these rollers constituting tangential supports for theworkpieces to be ground. As shown in Fig. 3, the axis of rotation of theroller 24 is in the same vertical plane as the axis of a'workpiece awhen in a grinding position, so that the point or points of tangencywill lie directly beneath the center of the workpiece.

The third tangential support for the workpieces comprises a largeflanged roller 25, to

which rotation is imparted and which therefore rotates the workpieces a,said roller being moved into and out of work-holding position to alloweach ground workpiece to be discharged from the machine and an ungroundworkpiece to be placed in grindin position. roller"25 is suitablyjournalled on a shaft 26 and suitable means such as a pulley 21 formedintegrally therewith is provided to rotate said roller,

., there beinga belt, not shown, running to the pulley 21 from anysuitable source of power. The shaft 26 is held by an arm 28 which ispivotally mounted on a bolt'or stud 29 of an oscillatory member 30, saidmember. 30 being mounted'for oscillation on the frame portion 20 bymeans of a projecting cylindrical portion 3I provided by the latter andan internal cylindrical bearing surface 32 provided by the former. Theaxis of oscillation of the member 30 coincides with the axis of rotationof the workpieces a. I

Referring now to all the figures, annular workpieces a to be ground maybe stacked one behind the other in a trough shaped magazine 33, thetrough of the magazine being inclined as shown, and the workpieces beingstacked therein so that they will roll toward the work-holding means asbest shown in Fig. 4. An escapement device 34 is provided so that theworkpieces will be released one at a time and only when desired, the

, construction and actuation of this device being after said roller 25moves back to its original and' normal position and in so doing guidesa'fresh workpiece a, which has been released by the escapement device34, into grinding position tangent to the rolls 23 and 24 and the roller25.

This movement of the roller 25 is accomplished.

through oscillation of the member 30, and the upward movement of theroller 25 occurs coincidentally with and is brought about by movement Tothat end the.

of the table I to the position of Fig. 1 in which the'grinding wheel iswithdrawn from the grindworking traverse in relation to a workpiecea,'it.

being understood that the fresh workpiece has reached the grindingposition by the time the wheel 4 starts to enter it.

The mechanism for imparting oscillations to the oscillatory member 30 inresponse to movement of the table I to remove and replace workpieces ingrinding position will now be described. Referring to Figs. 1 and 2 thetable I has fastened to the rear thereof a short bracket 35 whichprovides a hub portion 35a with a longitudinal hole. Through said holeextendslongitudinally a long rod 36 which is supported at the left handend by a bell crank lever 31 and is otherwise unsupported except by thehub portion 35a. The bell crank lever 31 is pivoted at 38 to the bridgeI8 and besides being connected to the rod 36 is connected by a link 39to one end of a lever 40 which is pivoted at H to the bridge I8. Theother end of the lever 40 has a connection to a depending arm 42provided by the oscillatory member 30, and as the lever 40 swings in oneplane and the oscillatory member 30 swings in a plane at right anglesthereto, this connection is made by means of a link bar 43 connected bypivot pins in different planes to short links 44 and 45; the link 44being'piv'otally connected at 4-6 to the lever 40 and the link 45 beingpivotally connected at 41 to the arm 42.

During the greater part of the travel of the table I to carry thegrinding wheel 4 away from a ground workpiece, the hub portion 350,simply slides over the rod 36 without effect thereon;

I member 30 to move the roller 25 up to the-magazine 33, where. itremains till the operator of the grinding machine starts it in operationagain as by the manual moving or" a control lever 49 which causes thetable I to move to the left, Fig. 1. On such return movement of thetable I, the hub portion 350. again passes over the rod 36 without.effect thereon until it comes in contact with a loose collar 50 mountedon said rod, which collar 50 is spaced by a stiff coil spring 53, from acollar 5|, the latter being fastened to said rod as by a pin 52. Thespring 53 is strong enough to resist compression until the linkagemechanism has caused the oscillatory member 30 to lower the roller 25 towork-holding position;- a new workpiece a has arrived at such positionjust prior to the entrance of the grinding wheel 4 into it, and theadditional movement of the table I to cause such entrance merely causescompression of the spring 53, the member 30 being prevented from movingbeyond the position shown. in Fig. 4 by a stop pin 54 which is engagedby the depending arm 42.

'I'he'machine of the present invention provides automatic means to causethe table of carriage I to move to the inoperative position shownin Fig.1; such may be set in operation by any kind of gage or calipermechanism, or it may be con-' trolled from the cross feed actuatingmechanism as shown, for example, in U. S. Letters Patent to Taylor, No.1,682,673, granted August 28, 1928. The present drawings disclose acontrol of the latter sort, and the essential elements thereof, so faras they relate to the present invention, will now be pointed out.Referring to Figs. 1 and '7, the left hand table dog 5, unlike the righthand table dog 6, is a pivotally mounted dog, being supportedby a pin,provided by a carrying block 56 adjustably positioned, as is the block51 of the dog 6, tothe table or carriage I. Below the dog 5 and in thepath thereof is a lever arm 58, which is pivotally mounted on a stud 59;one end of the lever arm is adapted, when raised, to cause the dog 5 tolift up and be carried clear of the reversing member 1, while the otherend of said lever arm incorporatesan armature 160. Said armature 60 liesjust above an electromagnet 6| which, when energized, draws the armaturedownwardly and consequently raises the right hand portion of the arm 58.

The hand wheel I5, or some part connected thereto or to the ratchetwheel 9 carries acam member 62. In the path of this cam member is anadjustable screw 63 carried by a contact making lever 64. This lever,when moved by the cam, closes anelectric circuit at 65 and causes anelectric current to flow through the magnet 6| from a generator 66 orany other suitable source, the current passing by way of a conductor 61from the generator to the magnet, by way of a conductor 68 from themagnet to the contact points at 65, the other lead of the generator andthe lever 64 being both grounded.

In the grinding of any given workpiece, the grinding wheel is caused tocut deeper and deeper by the intermittently actuated cross feedmechanism described hereinbefore; at any desired position of suchmechanism the cam 62 can be caused to engage and move the lever 64 thusclosing the circuit described and raising the lever arm 58. Raising ofthis arm causes the dog 5 to be lifted clear of the reversing member Ion the next subsequent travel of, the carriage I to the right, and saidcarriage therefore continues its movement uninterrupted until it isstopped by the means shown in the aforesaid patent to Heald and Guild,or by any other means. In the patent to Taylor referred to, there isshown a compensating mechanism which, in conjunction with a dressingmechanism such as shown at 69 controls the cross feed mechanisminerelation to the size of the grinding wheel, so that workpiecesuniform in size are produced; such com- Cal pensating and dressingmechanism is desirably incorporated into the present machine, but havingnothing to do with the present invention will not be described herein.

Referring now to Figs. 4, 5 and 6, upward movement of the roller 25,occasioned by outward travel of the carriage I as described, releases aworkpiece a in the magazine 33 by operation of the escapement 34. Thelatter comprises a pin I0 projecting through a slot II in the side ofthe magazine and normally engaging one of the workpieces a by contactwith its inner periphery. The pin I0 is mounted on the front face of ablock I2, said block being pivotally mounted on a pin I3 extendingbetween the ears I4, I4 provided on the side of a magazine 33. A springdevice I5 holds the block 12 normally in the position shown in Fig. 5;movement of the oscillatory member 30 to the position shown in Fig. 4causes an arm 15 formed integrally with said member 30 to engage anddepress a horizontally projecting portion 11 of the block I2, thuswithdrawing the pin III from engagement with a particular workpiece a Iand allowing, therefore, all of the workpieces a to move downwardly inthe trough magazine 33.

The parts are shown in this position in Fig. 4, the bottom workpiecebeing prevented from falling out of the magazine by the roller 25. When,as the table I moves to carry the grinding wheel 4 back into grindingposition, the oscillatory member 30 swings clockwise, Fig. 4, the arm 16releases the block I2 and the pin 10 engages the inside of the nextsucceeding workpiece a. The workpiece that has been released follows theroller 25 downwardly, resting partly on the roller .23 and revolving byreason of the revolution of the roller 25. From the view of Fig. 3, itwill be seen that the angular location of the rollers 25 and 23' duringthe grinding operation is such that the workpieces could not enterbetween these rollers if the roller 25 moved only in a path concentricwith the axis of ultimate rotation of the work. Therefore, means isprovided to move the roller in a radial direction to allow the workpieceto enter into grinding position. To that'end there is formed integrallywith the frame portion 20 a cam I8, which acts against a roller I9 whichis mounted on a ball bearing, not shown, carried by the shaft 26. Aspring 80, connected to pins 8| and 82 provided by the oscillatorymember 30 and the arm 28 respectively, tends to hold the roller 25 closeto the axis of the workpiece rotation, with .the roller I9 in engagementwith the cam I8. The parts are substantially in this position when aworkpiece a is released; as the oscillatory member 30 swings downwardly,the roller 19 rides on the cam I8 and the driving roll 25 is swungoutwardly. Just. before the parts have come to the position shown inFig. 3, the rollers 23 and 25 have separated enough to allow theworkpiece a to drop through onto the roller 24; the gap between therollers 24 and 25 at this time is not large enough to allow theworkpiece a to drop out of the machine, and by reason of a sharpinclination in the cam I8, the roller 25 moves rapidly and practicallyvertically downward, following the workpiece a into grinding positionand holding it there by the pressure of a spring 80.

, In the operation of the machine, the operator Q has only to load thetrough magazine 33 with a plurality of workpieces, depressing theprojecting portions" of the block I2 and allowing the pin III to enterthe inside of a given workpiece to hold all of them in position in themagazine. The table I being then in the position of Fig. l and thedriving roller 25 being raised as shown, the machine is started byshifting the main control lever 49.. This causes a single workpiece a tobe released and to be guided down into grinding position as alreadydescribed. It should be noted that the rotation of the pulley 25 helpsto force the workpiece down and the cam I8 need only open up the roller25 enough to allow the workpiece a. just room to squeeze through. Thecam 18 should be shaped so that the roller .25 will drop into positionrapidly and hold the workpiece a without excessive rebound as it strikesthe roller 24; the flanges on all three rollers 23, 24 and 25 hold theworkpiece longitudinally of the axis thereof, and it should be noted inthis connection that these flanges are slightly wedge shaped in order togrip the workpiece firmly.

The workpiece is now automatically ground to the required internaldiameter, and when such diameter is attained, the table I runsoutwardlyin response to lifting of the pivotallymounted dog 5', asdescribed. The roller 25 then moves upwardly, releasing the groundworkpiece afrom grinding position, and releasing another workpiece a inthe magazine 33. The ground workpiece will drop out of the machine,because it is still rotating, and the friction on the roller 24 tends tocause it to move to the left, Fig. 3, and as it is directly over theaxis of said roller 24, a slight amount of" movement suffices to causeit to drop out.

It should be observed that instead of providing the means set forth inthe aforesaid patent to Heald and Guild to stop the table I in itsoutward position when a particular workpiece is finished, an additionaltable dog could be provided which would swing over the reversing memberI and start thetable inwardly again.

Such simple addition to the machine here shown would make the machinecompletely automatic, so. that the operator would not have to-start themachine again after each grinding operation, except for the fact thatthe cross slide mechanism would need retraction to allow the wheel 4 toenter a new workpiece. But the latter may also be provided and anexemplary embodiment thereof is shown in my prior application Serial No.99,287, filed April 2, 1926, and it should be understood that thepresent machine can be made completely automatic by the incorporation ofthis table reversing dog and automatic wheel retraction mechanism, bothof which are shown in said application. 7

Instead of rotating the workpiece a by means of rotation imparted to theroll 25, it might be rotated by rotation imparted to either of the rolls23 or 24, particularly as these are mounted on a stationary axis, andindeed both of these rolls could be positively driven to rotate theworkpiece within the scope of my invention. Similarly, instead ofcausing only the roll 25 to move to allow workpieces to be received inworkholding position and discharged therefrom, either or both of therolls 23 and 24 could be moved to permit the introduction or discharge.of a workpiece either with or without the movement of the roll 25. Theabove and many other changes in the actual embodiment of the inventionfall within the scope of the appended claims.

I claim:

1. In a machine of the class described, the combination with a pluralityof tangential rolls to hold a workpiece in position to be operated upon,certain of said rolls being resiliently urged against said workpiece tohold it in position and certain of said rolls being rotated to rotatesaid workpiece, means for moving one of said rolls into and out ofworkholding position to allow finished workpieces to be removed andunfinished workpieces to be placed in workholding position, of amagazine adapted to hold a plurality of workpieces and escapement meansto release said.

workpieces one by one from said magazine to allow them to be receivedbetween said rolls.

2. In a machine of the class described, the combintion with a pluralityof rolls for holding workpieces in positionv to be operated upon bytangential engagement with them, and means. for moving one of said rollsinto workholding position where it presses resiliently against aworkpiece and for moving said roll away from the other rolls to allow afinished workpiece to be removed from operating position and a freshworkpiece to be introduced into operating position, of means forintroducing the fresh workpieces into operating position against theresilient pressure of said movable roll, said means consisting partly inthe rotation imparted to one of said rolls whereby the workpiece isrotated.

3. ma machine of the class described, the combination with workholdingmeans comprising a plurality of rolls to hold a workplace in operatingposition, and means for moving one of said rolls in relation to theother rolls to open a gap therebetween to permit a finished workpiece tobe removed from the machine and a fresh workpiece to be introduced intooperating position, of a magazine located above said rolls, andescapement means to allow workpieces to descend by gravity one by 'oneinto operating position.

'4. Ina machine of the class described, the combination with workholdingmeans comprising a plurality of rolls to hold a workpiece in operatingposition, and means for moving one of said rolls in relation to theother rolls to open a gap therebetween to permit a finished workpiece tobe removed from the machine and a fresh workpieceto be introduced intooperating position, of a trough-shaped magazine adapted to hold roundworkpieces in a position where they will roll downwardly if released,said magazine being located above said workholding means, and escapementmeans to release said workpieces one by one to allow them to movedownwardly by gravity into workholding position.

5. In a machine of the class described, the combination with workholdingmeans comprising a plurality of rollsto hold a workpiece in operatingposition, and means for moving one of said rolls in relation to theother rolls to open a gap therebetween to permit a finished workpiece tobe removed from the machine and a fresh workpiece to be introduced intooperating position, of a trough-shaped magazine adapted to hold roundworkpieces in a position where they will roll downwardly'if released,said magazine being located above said workholding means, and escapement means to release said workpieces one by one to allow them to movedownwardly by gravity into workholding position, said escapement meansbe ing operated by the movement of the movable roll away from the otherrolls.

6. In a machine of the class described, workholding and loadingmechanism comprising a pair of rotatable rolls mounted 'on stationaryaxes, a third rotatable roll, a magazine adapted to hold a plurality ofworkpieces, and means for moving said third roll to and from saidmagazine to guide 'a workpiece'into operating position.

7. In a machine of the class described, workholding and loadingmechanism comprising a plurality of rotatable rolls certain of which aremovable with respect to the others to" open up the workholding means toallow workpieces to be inserted and ejected therefrom, a magazine forholding a plurality of workpieces, and escapement means for releasingsaid workpieces from said magazine one by one, said escapement meanscomprising in part the movable roll and in part a separate escapementmember.

8. In a machine of the class described, workholding and loadingmechanism comprising a plurality of rotatable rolls one of which ismovable with respect to the others to open up the workholding means toallow workpieces to be inserted and ejected therefrom, a magazine forholding a plurality of workpieces, and escapement means for releasingsaid workpieces from said magazine one by one, said escapement meanscomprising in'part the movable roll and in part 75 a separate escapementmember, the latter being operated by the means that move said roll.

9. A grinding machine having, in combination, a carriage having an idleposition and a position in which it reciprocates, workholding meanscomprising a plurality of rotatable rolls one of which is movable withrespect to the others to introduce and discharge workpieces, andconnections between said movable roll and said carriage to cause theformer to be moved by the latter when it nears the idle position, andto. be moved in the reverse direction when the carriage nears theposition in'which it reciprocates, and means to allow the carriage toreciprocate without effect upon the said movable roll.

10. In a machine of the class described, a pair of rolls mounted onfixed axes, a third roll which in combination with the first twoconstitutes workholding means, oscillating means for moving the thirdroll, a mounting for said roll on said oscillating means whereby it maymove towards or away from the axis of the workpiece, and can means toguide said movable roll upon movement thereof, whereby to facilitate theintroduction of a workpiece into operating position.

11. In a machine of the class described, the combination with means forperipherally supporting and frictionally rotating a workpiece foroperation on an internal surface thereof, said means comprising a rollmounted upon a fixed axis and engaging the periphery of the workpiece,and an opposed roll resiliently urged against the workpiece and engagingthe periphery thereof on the opposite side, 'and'a supporting memberbeneath said rolls and engaging the periphery of said workpiece, one ofsaid rolls being rotated to procure rotation of the workpiece, and meansfor moving said second roll into and out of workholding position toallow finished workpieces to be removed from, and unfinished workpiecesto be placed in workholding position, of a magazine adapted to hold aplurality of workpieces and escapement means to release said workpiecesone by one from said magazine to allow them to be received between saidrolls.

12. In a machine of the class described, the combination with means forperipherally supporting and frictionally rotating a workpiece, saidmeans comprising a roll mounted on a fixed axis and engageable with theperiphery of the workpiece, an opposed roll on a movable axis engagingthe periphery of said workpiece on the opposite side thereof, and-asupporting member beneath said rolls and engaging the periphery of theworkpiece, one of said rolls being rotated to procure rotation of theworkpiece, and means for moving said second roll away from said otherroll to open a gap therebetween to permit removal of a finishedworkpiece and insertion of an unfinished workpiece between said rolls,of a magazine located above said rolls, and escapement means to allowworkpieces to descend by gravity one by one into operating position.

13. In a machine of the class described, workholding and loadingmechanism comprising opposed rolls, one of which is mounted on astationary axis, said rolls being engageable with the periphery of aworkpiece, one of .said rolls'being rotated to procure rotation of theworkpiece, a supporting member beneath said rolls andrengageable withthe periphery of the workpiece, the other of said rolls being movablewith respect to the roll on the fixed axis to open up the workholdingmeans to allow workpieces to be inserted and ejected therefrom, amagazine for holding a plurality of workpieces and escapement means oneby one, said escapement means comprising in part the movable roll and inpart a separate escapement member.

14. In a grinding machine, the combination with a grinding member and awork-supporting member, the lattercomprising spaced rolls for engagementwith the periphery of a workpiece on opposite sides thereof, and asupport beneath said rolls for engagement with the periphery of 'saidworkpiece, one of said rolls being rotated to procure rotation of theworkpiece, and a table or carriage carrying one of said members adaptedwhen reciprocated to produce a relative working traverse between saidwheel and workpiece, of means responsive to the table movement toprocure discharge of a'finished workpiece from said worksupportingmember.

15. In a grinding machine, the combination with a grinding member and awork-supporting member, the latter comprising spaced rolls forengagement with the periphery of a workpiece on opposite sides thereof,and a support beneath said rolls for engagement with the periphery ofsaid workpiece, one of said rolls being rotated to procure rotation ofthe workpiece, and a table or carriage carrying one of said membersadapted when reciprocated to produce a relative working traverse betweensaid wheel and workpiece, of means responsive to the table movement toprocure discharge of a finished workpiece from said work-supportingmember and to position an unfinished workpiece in said member.

16. A grinding machine having in combination, a carriage having an idleposition-and a position in which it reciprocates, workholding meanscomprising a pair of rolls in opposed relation for engagement with theperiphery of a workpiece on opposite sides thereof, and a work-supportbeneath said rolls and engaging the periphery of said workpiece, one ofsaid rolls being movable with respect to the other for removal andinsertion of workpieces therebetween, and connections between saidmovable roll and said carriage to cause the former to be moved by thelatter when it approaches the idle position and to be moved in thereverse direction when the carriage approaches the position in which itreciprocates.

17. In a machine of the class described, a pair of rolls mounted inopposed relation for engagement'with the periphery of a workpiece onopposite sides'thereof, a support beneath said rolls and also engagingthe periphery of said workpiece, oscillating means for moving one ofsaid rolls, a mounting for said roll on said oscillating means, wherebyit may move toward or away from the axis of the workpiece, and cam meansto guide said movable roll upon movement thereof to facilitate theintroduction of a workpiece into operating position.

18. In a grinding machine, 'an internal grinding wheel, means forperipherally supporting and frictionally rotating a workpiece for agrinding operation on an internal surface thereof, a table,reciprocation of which procures a traverse of the grinding wheel overthe surface of the workpiece, and means responsive to movement of saidtable to procure discharge of a finished workpiece from the supportingmeans.

19. In a grinding machine, an internal grinding wheel, means forperipherally supporting and frictionally rotating a workpiece for agrinding operation on an internal surface thereof, a table,reciprocation of which procures a traverse of the rinding -wheel overthe surface of the workpiece, andmeans responsive to movement ofsaidtable to procure discharge of a finished work- ;piece from thesupporting means, and to position ,operation on an internal surfacethereof, a table,

reciprocation of which procures a traverse of the grinding wheel overthe surface of the workpiece, means under the control of the grindingoperation for procuring an extended movement of the table for an axialseparation of the grinding wheel and the workpiece, and means responsiveto said extended ,movement of the table to procure .discharge of, afinished workpiece from the supporting means. i l

21. In a grinding machine, an internal grinding member and awork-supporting member, the latter including a regulating wheel, asupport spaced therefrom and a pressure roll for holding a workpieceagainst the support and regulating wheel, a table on which one of saidmembers is mounted, means for procuring a crossfeed movement between thegrinding member and a workpiece in the work-supporting member, and meansresponsive to the crossfeed movement and operative when the cuttingsurface of the grinding wheel reaches a predetermined position relativeto the surface of the regulating wheel for procuring a rnnout of thetablefor separating the grinding member from the workpiece in thework-supporting member..

. 22. In a grinding machine, an internal grinding member and awork-supporting member, the latter including a regulating wheel, asupport spaced therefrom and a pressure roll for holding a workpieceagainst the support and regulating wheel, a table on which one of saidmembers is mounted, means for procuring a crossfeed movement between.the grinding member and a workpiece in the work-supporting member, andmeans operative when the cutting surface of the grinding member reachesa predetermined position relative to the work-supporting member forprocuring an extended movement of the table for an axial separationbetween thegrinding member and the workpiece in the work-supportingmember.

-23. In a grinding machine, an internal grinding member and awork-supporting member, the latter including a regulating wheel, asupport spaced therefrom and a pressure roll for holding tion.

aoosms aworkpiece against the support and regulating wheel, a table onwhich one of said members is' her and the workpiece in the"work-supporting member when the workpiece reaches a terminedsize.

24. In a grinding m'achine, an internal grinding member and awork-supporting member, the latter including a regulating wheel, asupport spaced therefrom and a pressure roll for holding a workpieceagainstthe support and regulating wheel, a table on which one of saidmembers is mounted, size controllingmeans for procuring an extended.movement of thetable -for an axial separation between. the grindingmember-and a workpiece in the workesupportingmember when said workpiecereaches apredetermined size, and means. responsive to said extendedmovement of the table for procuring aradial discharge of the workpiecefrom the supporting member.

25. In a grinding machine, the combination with a grinding member and awork-supporting member, the latter comprising spaced rolls forengagement with the periphery of-.- a workpiece on opposite sidesthereof, and a support beneath said rollsfor engagement withtheperiphery of saidworkpiece, one of said rolls being rotated toprocurerotation of the workpiece, and a table or carriage carrying oneof said members adapted, when reciprocated, to' produce a relativeworking traverse between said wheel and workpiece, of means responsivetothe table movement to procure a radial discharge ofa finished. workpiecefrom said work-supporting membenand to position an unfinished workpiecein said member. a

26. In amachine of the class described,- a pair of rolls mounted inopposed relation for engagement with the periphery of a workpiece .onopposite sides thereof, a supp rt beneathsaid rolls and also engagingthe periphery of. said workpiece, oscillating means for moving one -ofsaid rolls about an axis coinciding substantially with the axis of saidworkpiece, a mounting for said roll on said oscillating means wherebyitmay be moved toward or away from the axis of the workpiece, and cammeans for guiding saidmovable roll upon, movement thereof to facilitate.the introduction of a workpiece into operative posi- 01mm: J. um.

prede-

